Lots of smoke in the midrange would indicate that it's rich but some of the other things you are describing makes it sound lean.

Next time you run it, fire it at about 1/4 throttle and let it run for a minute or two before you go to full throttle. Let it go full throttle for about 30 seconds then set the HS needle. Use a tach if you have a tin ear. You only want it 200 or 300 off the peak at full throttle. That's usually about 2 clicks at most. If you go 1/4 turn that is way too much.

Then pull it back to a fast idle, maybe 3000 to 3500 or so and listen to it. If the rpm increases a little, richen the reg a bit, if it starts to slow down gradually lean the reg a bit. I go 1/4 turn at a time until it's about right, then 1/8 turn. Then go to full throttle and see if it barfs out a bunch of smoke and raw fuel. Keep going from the from the high idle to full and keep adjusting the reg until you get it right. Every time you make a regulator adjustment, go back to full throttle then down again to check it. Bear in mind that it's better to be just slightly rich in the mid range than lean, but just a little.

After clearing it out at full throttle and being satisfied with the transition, drop back to idle at about 2000 to 2200. Let it sit there until the idle rpm increases or decreases. If it does neither, it is set correctly. If the rpm rises slowly, it is too lean. Correct this by screwing the idle screw in (clockwise) 1/8 to 1/4 turn at a time until you are satisfied that the idle is steady. On the other hand, if the idle gradually slows down, it is too rich and you will need to go the opposite way on the idle needle.,

One more thing, check the valve setting. It should be .003" on both valves. If the valves are too tight the engine will not idle or transition well.

Hope this will help.